The most common site of a mediastinal tumor is within the anterior mediastinum [3, 4]. Anterior mediastinal tumors commonly include: thymoma, teratoma, ectopic thyroid tissue and lymphoma. It is very rare to have neurogenic tumors located in the anterior mediastinum which are more commonly located in the posterior mediastinum [5].

The most common overall type of mediastinal tumor in both adults and children are neurogenic in nature and occur in the posterior mediastinum. Schwannoma is a type of mediastinal neurogenic tumor and is typically asymptomatic, however symptoms may occur due to the mass effect of the growing tumor (Marchevsky).

Schwannoma is a slow growing benign neural sheath tumor of the peripheral nervous system [6, 7]. Forty-five percent of schwannomas occur in the head and neck with only about nine percent occurring in the mediastinum(Kapoor). Mediastinal schwannomas most commonly occur from the sympathetic trunks or intercostal nerves in the paravertebral location; however, our patient was found to have an anterior schwannoma possibly originating from intercostal nerve branches in the anterolateral chest wall location.

Histopathological features consistent with schwannoma showed positive S100 and OSX10, and negative for cytokeratin AE1/AE3, desmin, CD34, melanoma cocktail, p63, and STAT6 [8]. This finding is crucial for confirming the diagnosis and was consistent with the staining results obtained from our specimen (Fig. 4).

Histologic sections reveal a spindle cell neoplasm forming short fascicles, and admixed cellular Antoni A and hypocellular Antoni B. The tumor cells are bland with abundant eosinophilic cytoplasm. Verocay bodies are seen. Mitotic figures are not identified. Degenerative changes and thick-walled vessels are present

Our patient presents with a case of a symptomatic 12.5 x 8.5 x 6.0 cm anterior mediastinal mass with pathological stains consistent with Schwannoma. Symptomatology of the patient included syncope and right upper/lower extremity weakness. Excluding patients with neurofibromatosis, it is exceedingly rare to have concurrent lesions elsewhere. Our patient had a concurrent lesion in his cervical spine accounting for his motor deficits for which he would be seeking treatment in the future after recovery from his initial surgery. Anterior mediastinal schwannomas are rare, indolent in nature, and benign. However, they can lead to significant compressive symptoms of structures within the anterior mediastinum including airway or cardiovascular compromise as well as neurological deficits [9, 10]. This presentation poses an early diagnostic challenge and therefore our paper intends to share awareness for the development of high clinical suspicion of this disease process.

From our literature review no consensus on a standardized treatment modality has been proposed. The goal of this paper is to raise awareness of the rare anterior mediastinal tumor and to advocate for thorough investigation for concurrent lesions and recommend surgical resection of these masses to avoid potential complications.